Electric switch.



No. 875,029. PATBNTED DB0. s1, 1907. J. J. Woon.

ELECTRIC SWITCH.

APPLIGATION FILED APn.z.19o5.

INVENTOR. l

JAMES J. WOOD, OF FORT WAYNE, INDIANA.

' ELECTRIC SWITCH.

Specification of Letters Patent. Application filed April 28| 1905. `Serial No. 257,838.

Patented Dec. 31, 1907.

To all whom it may concern:

Be it known that l, JAMES J. Woon, a citizen of the United States, residing at Fort j Wayne, in the county of Allen and State of Indiana, have invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

This invention relates to electric switches adapted for various uses. In its specific form this switch was designed and is especially adapted for use in a prepayment electric meter, for cutting off the electric light when the meter makes its nal counting-down movement upon the measuring out of the amount of electric energy for which I the customer has pre aid. -The switch, however, is not confine to this use, but is adapted to many other uses.

Flgure 1 of the accompanying drawings is a front elevation of the switch in the closed position; Fig. 2 is a side elevation partly in vertical mid-section; Fig. 3 is a front elevation in the open position, -partly broken away in section; Fig. 4 is a sectional front i elevation showing the switch operating cam; i Fig. 5 is an enlarged fragment of the circuit closing springs and their mounting; and Fig. 6 is a vertical cross-section thereof on the line 6 6 in Fig. 5.

Let A A and B B/ represent contact terminals which are preferably constructed to serve also as binding posts, in which are confined the ends of the circuit wires 1, 2, 3 and 4 respectively. The respective contact terminals are, when the switch is closed, connected by conducting bridges C and C earried by any suitable part which will move them into and out'of Contact with the terminals. `The bridge C joins the terminals A A', and the bridge C joins the terminals B B. These bridges are carried on a crossbar or yoke D. This cross-bar carries the bridges at or near its opposite ends and .is connected between them and preferably at i its middle to a bearing device by which it is moved bodily, and upon which it can. turn or rock to a sufficient extent to equaliz(` the pressure of the respective bridges.` The cross-bar D is shown as a plate of insulating material, strengthened on opposite sides by metal plates or cheek-pieces c (1, which are fastened by rivets extending through it. i The cross-bar D is engaged at its middle by' an upright rod E which is vertically movable to open or close the switch. The rod E Slides in a fixed eye F above, shown as projecting from a' back plate G, and its downward movement is imited by a head E which abuts against the eye F. The lower end of the rod E is jointed to a lever arm H by the rocking movement of which the rod is moved. Preferably this joint is made by means of a pin 71y projecting rearwardly from the a'rm Hand entering a hole in the rod, so that the switch can be easily taken apart by simply displacing the arm H so as to withdraw this pin.

The arm H is shown as projecting from a rock shaft I, which is shown as a sleeve turning on a fixed pin 'i projecting from a bracket y' forming part of the fixed frame 1.', so that the lever ll may be easily displaced by drawing the sleeve l forwardly ofi' from the pin fi.

From the opposite end of the rock shaft or sleeve l projects an arm J carrying on its upper end a roller which may enter a cam notch b in the outer cylindrical surface c of a wheel or disk K. A spring is applied to 'press the arm J against the cam surface b c, and to press the switch open. This spring is most conveniently applied as a helical spring li coiled around the rod E and confined between the eye F and the top of the cross-bar D, so that it exerts a downward pressure upon `this bar and through the rod E and arm H upon the arm J. 'Another and stii'l'er spring M is interposed at some-convenient point between the cross-bar D and the roller arm J, preferably directly beneath the cross-bar and between it and a nut d adjustable upon the lower portion of the rod E, whereby the compression of the spring M may be adjusted.

In a prepayment electric meter, the wheel -K is the part, or is connected with the part,

which moves in one direction to count up thc inserted coins, and in the opposite direction to count down as the current is measured out by the meter. For a detailed description of such a prepayment meter, reference may be mad(l to my application No. 235,412, iiled December 3, 1904, (patented December 5, 1905, No. 806,722 where the wheel li is called a credit indicator and lettered 'lhe particular construction and operation ofthe wheel forms no necessary part of my present invention, except that it provides the cam surface t c for operating the lever arm J, and therefore serves as an illustration of a movable cam for opi-rating the switch. My improved switch is especially adapted to be operated by such a cam, but

' Or by any other mechanism an upward thrust may be imparted to the rod E in order to lift the yoke D from the open position shown iii Fig. 3 to the closed position shown in Fig. 1. During this movement the conducting bridges C C strike the respective 'pairs of terminals A A and B B so as to electrically connect the two terminals of each pair, and

thereb close the circuit from wire l to wire 2 and om wire 8 to wire 4 (Fig. l). During this closing movement the spring L is compressed until the bridges are pressed firmly against the terminals, whereupon the movement of the bar D ceases, and this should occur before the end of the movement iniparted to the rod lil, so that during the remaining movement of the latter the spring M shall be compressed in order to take up the requisite lost motion and press the respective bridges firmly but yieldingly against t e terminals. On the return movement of the wheel K, when the roller on the arm l drops back into the cam-notch b, the iod E is pressed down by the spring L, which throws the switch open.

The cross-bar D is loosely enough connected to the rod E so that it may rock on the rod in order to equalize the pressure between the two bridges and (3. Preferably the rod E passes through a hole in the cross-bar, which has a sufliciently loose iit to permit this rocking movement. Each of the bridges also is loosely connected to the cross-bar, in order that it may rock thereon and equalize the pressure at opposite ends of the bridge against the respective terminals. The preferred construction to this end is that shown, wherein the bridge is fastened by one or more rivets or otherwise to a yoke or stirrup-piece e, which is pivoted at f to the cross-bar D with siilicient looseness so as to be able to rock on'tliis bar. The described. construction insures that the pressure communicated through the spring M shall be equally divided by the cross-bar between the two bridges, and shall be equally divided by the rockino' bridges between the opposite ends thereof; so that equal and uniform cont-act is maintained against the four terminals or binding posts.

The bridges C C are best constructed as metallic brushes'making end vcontact with the respective terminals. Each bridge consists of several leaves or lammse of suitable resilient sheet metal fastened at their middles preferably by being riveted to the stirrup-piece c, and having their ends upturned so as to make edge contact with the under faces of the terminals. rlhese brushes or laminal bridges partially flatten out during the closing movement, so that the edges of the laminas rub against the contact faces of the terminals and thereby keep these faces, as well as their own contacting surfaces, clean and bright.

lt is practically important to elongate one of the laminae, preferably the outer oneas shown at g, so that in thc closing movement this outer lamina touches the terminals in advance of the other laminas, and in the opening .movement this outer lamina g is the last to break contact withthe terminals, so that the spark which occurs at the breaking of the circuit, affects only this outer laminas g, and is not effective to pit, burn or corrode the contacting surfaces of the other or main laminas of the bridge, whereby the surfaces of these latter are. kept bright so as to make a clean and perfect Contact. rlhe outer lamina g is also preferably bent slightly away from the remaining ones, as shown in Fig. 5, so that in breaking contact the s ark will be confined to the outer portion o the face of the terminal, in order that any pitting or corroding by this spark shall occur b'eyond the portion of the lower face of the terminal with which the other or main laminae make contact.

My invention is susceptible of certain modifications, so that it must not be inferred from the particularity with which its details of construction are herein described, that these details are necessarily essential. The switch is shown as a double-pole switch, which is preferable but not indispensable.

The invention is not limited to a camoperated switch, but may be used in connection with other means for operating it.

W'hat I claim is1- 1. An electric switch comprising two pairs of contact terminals, two conducting bridges' for uniting the two terminals of the respective pairs, a cross-bar carrying said bridges, and actuating means engaging said crossbar between said bridges with suflicient looseiiess to enable the cross-bar to rock and divide the pressure applied thereto between said bridges.

2. An electric switch comprising two pairs of contact terminals, two metallic bridges for electrically uniting the two terminals of the respective pairs, a cross-bar to which said bridges are pivotally connecteil, and actuating means loosely engaging' said cross-bar between the bridges, whereby the pressure applied thereby tosaid cross-bar is divided and distributed equally to the four contact terminals.

3. An electric switch comprising two pairs of' circuit terminals, two .metallic .bridges for connecting the two terminals of the respective pairs7 a rocking cross-bar Carrying said bridges, a movable rod loosely engaging said cross-bar between them, and means for moving said' rod to displace the cross-intr and open or close the Switch.

4. In an electric Switch, the combination of a cross-bar carrying the circuit closing contacts, a movable rod carryingl said erossbar, a Spring' L tending` constantly lo open the switch, an actuating' part engaging said rod to close the switch against said spring, a stronger spring M, and an adjustable part (Z between which and said cross-bar said 'spring is confined, and Wl'lereby its stress may be adjusted.

5. In an eleetriel Switch, the combination detachable actuating lever arm H in front of' said rod having :fixed to it a rearwardly projecting pin fr freelrT entering' said pivot hole, whereby the lever may be disconnected and displaced forwardly by withdrawing its pin from said hole,

ln witness whereof, l have hereunto signed. in v name in the presence ot two subscribing witnesses.

I'i. S. HUN'UNG, A. A. Seem. 

